The length and breadth of a rectangular sheet are 16.2 cm and 10.1cm, respectively. The area of the sheet in appropriate significant figures and error is

Options

A. `164+-3cm^(2)`
B. `163.62+-2.6cm^(2)`
C. `163.6+-2.6cm^(2)`
D. `163.62+-3cm^(2)`

Answer

A

Explanation

Let length and breadth f a rectangular sheet are measured by using a metre scale as 16.2 cm and 10.1 cm respectively. Each measurement has three significant figures. ltrgt `therefore` Length l can e written as
`l=16.2+-0.1cm=16.2cm+-0.6%`
Similarly, the breadth b can be written as
`b=10.1+-0.1cm=10.1cm+-1%`
Area of the sheet,
`A=lxxb=163.62cm^2+-1.6%=163.62+-2.6cm^(2)`
Therefore, as per rule, area will have only three significant figures and error will have only one significant figure. Rounding off, we get `A=164+-3cm^(2)`